browser_shutdown_multi_reference.js

Enable keyboard shortcuts

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

"use strict";

add_task(async function () {

  info("Creating a service");

  // Create a11y service.

  const [a11yInitObserver, a11yInit] = initAccService();

  await a11yInitObserver;

  let accService1 = Cc["@mozilla.org/accessibilityService;1"].getService(

    Ci.nsIAccessibilityService

);

  await a11yInit;

  ok(accService1, "Service initialized");

  // Add another reference to a11y service. This will not trigger

  // 'a11y-init-or-shutdown' event

  let accService2 = Cc["@mozilla.org/accessibilityService;1"].getService(

    Ci.nsIAccessibilityService

);

  ok(accService2, "Service initialized");

  info("Removing all service references");

  let canShutdown = false;

  // This promise will resolve only if canShutdown flag is set to true. If

  // 'a11y-init-or-shutdown' event with '0' flag comes before it can be shut

  // down, the promise will reject.

  const [a11yShutdownObserver, a11yShutdownPromise] = shutdownAccService();

  await a11yShutdownObserver;

  const a11yShutdown = new Promise((resolve, reject) =>

    a11yShutdownPromise.then(() =>

      canShutdown

        ? resolve()

        : reject("Accessible service was shut down incorrectly")

);

  // Remove first a11y service reference.

  accService1 = null;

  ok(!accService1, "Service is removed");

  // Force garbage collection that should not trigger shutdown because there is

  // another reference.

  forceGC();

  // Have some breathing room when removing a11y service references.

  await TestUtils.waitForTick();

  // Now allow a11y service to shutdown.

  canShutdown = true;

  // Remove last a11y service reference.

  accService2 = null;

  ok(!accService2, "Service is removed");

  // Force garbage collection that should trigger shutdown.

  forceGC();

  await a11yShutdown;

});